esp32: Enable native emitter.

ports/esp32/main.c

@@ -172,3 +172,13 @@ void nlr_jump_fail(void *val) {
 void mbedtls_debug_set_threshold(int threshold) {
     (void)threshold;
 }
+
+void *esp_native_code_commit(void *buf, size_t len) {
+    len = (len + 3) & ~3;
+    uint32_t *p = heap_caps_malloc(len, MALLOC_CAP_EXEC);
+    if (p == NULL) {
+        m_malloc_fail(len);
+    }
+    memcpy(p, buf, len);
+    return p;
+}

ports/esp32/mpconfigport.h

@@ -20,6 +20,9 @@
 
 // emitters
 #define MICROPY_PERSISTENT_CODE_LOAD        (1)
+#define MICROPY_EMIT_XTENSAWIN              (1)
+void *esp_native_code_commit(void*, size_t);
+#define MP_PLAT_COMMIT_EXEC(buf, len) esp_native_code_commit(buf, len)
 
 // compiler configuration
 #define MICROPY_COMP_MODULE_CONST           (1)